Mistaken Identity
by Holz9364
Summary: A strange case causes the mysterious British group the MoM to interfere in Castle & Beckett's case, causing all sorts of chaos. Set in S5 for Castle & post hogwarts, non cannon for HP. Oneshot!


Mistaken Identity

The day had started out like any other for Richard Castle and Kate Beckett; they'd woken up, checked the paper and argued about the headline, as usual. Then they had driven to the precinct where they found out after literally two seconds that they had a case.

Castle got excited like a kid in a candy shop, Beckett rolled her eyes, Ryan and Esposito smirked and got into their car, Beckett and Castle followed, bickering all the way to the crime scene.

It was after they arrived at the crime scene that all hell broke loose and a fairly ordinary day become one Castle would remember for a very long time.

'What we got?' Beckett asked Lanie as she walked into the 2nd floor apartment where a dead body was sprawled in the middle of the living room.

Lanie looked up from the body with a frown on her face, 'You tell me,' she said, standing up, 'this guy seems perfectly healthy, no visible cause of death.'

'Maybe he was injected,' Castle piped in, trying to be useful as ever, Beckett smiled, she found it cute.

Lanie nodded, 'if he was, then it was in a pretty remote place if you know what I mean,' she said, raising her eyebrows. Castle grimaced, 'ouch, poor guy.'

'I'll know more when I get him back to the lab,' Lanie said simply, ignoring Castles comment, Beckett thanked her as she left the room and headed back to her van to get the equipment that would transport the corpse to the morgue.

Beckett had already put her gloves on so she reached down into the mans pocket and pulled out his wallet, the picture on his driving license was dated and there was something else odd about it, 'Hey Castle…' she said, frowning as she examined it more closely, 'our vic is Phillip Hamilton-Brown… check his driving license, its British.'

Castle snorted in amusement as he looked at the driving license, 'Phillip Hamilton-Brown, could it get more British?'

'Actually Castle, Phillip is a French name, it's only associated with England because Prince Phillip is married to the Queen,' Beckett said matter of factly, 'and don't mock the dead, it's not cool.'

'Yes boss,' Castle murmured in amusement as he handed her the driver's license which she put back in the wallet which was then bagged as evidence.

'Come on, let's go back to the precinct and see what we can pull up on this guy,' Beckett said with another glance around the room which was perfect, nothing broken or out of place, it didn't look like anyone had been here, 'I don't think there is much more we can do here.'

'If the killer tidied up after himself forensics will find prints,' Castle said as he and Beckett made their way to the front of the building to meet Esposito and Ryan.

'Unless the killer wore gloves,' Beckett noted, adding, 'or unless he knew his killer and was taken by surprise.'

'Hm,' Castle said thoughtfully, 'his eyes were closed, maybe somebody shut them, like in that case with Esposito's old partner.'

'That's a good idea,' Beckett said, sounding surprised as usual as she pulled her cell from her pocket, 'I'll call Lanie and ask her to check.'

Castle smirked and walked ahead as Beckett made the call, 'So guys,' he said to the boys when he reached them standing by the car, 'this is a cool one right?'

'I guess,' Ryan said slowly, 'but isn't it kind of morally wrong to find murder cool?'

'Ryan you think everything is morally wrong,' Esposito commented good naturedly.

'So did you find anything?' a new voice chipped in.

'Oh hey Beckett,' Ryan said, while Esposito jumped straight into the case, 'yeah our guy is a British runaway, he doesn't seem to be working over here, but he's on the run from something.'

'Did you talk to anyone at Interpol?' Beckett asked, that small frown still on her face which meant she was mulling things over.

'Yeah, but he couldn't give me much,' Esposito said, it was clear he was irritated by this fact, 'all they know is that he's wanted in England, Scotland, Wales, Ireland and several countries in Europe.'

'And who is the detective in charge of the case?' Beckett asked, the frown deepening.

'That's the weird thing, no one that we're allowed to talk too. The guy at Interpol said it was classified,' Castle smirked at Esposito's annoyance that he couldn't use his Detective status to wheedle information out of someone.

'By who?' Beckett barked, getting more irritated and confused by the moment.

'Some British squad called MoM.'

'MoM?' Castle asked, chuckling, 'as in Mom? Well I guess Moms the word…' he trailed off and then stopped laughing when he realised the others were glaring at him, not laughing with him, 'so I guess we don't like it when this happens?'

'No, we don't,' Beckett barked, 'get in the car Castle,' she ordered as she got in the driver's seat and slammed the door.

Ryan whistled and Esposito whispered, 'Castle, have sex with her later, it might put her in a good mood.'

Castle merely winked at the two Detectives and jumped into the passenger seat of Beckett's car.

* * *

When Beckett stormed into the morgue she was praying Lanie could tell her more, otherwise she had a feeling this case could get more and more frustrating by the second.

'Please tell me you've got something!'

Lanie could tell from the pained look on Castles face that something was annoying Beckett and after her initial examination of the body she didn't blame the detective, 'I don't got something,' Lanie said, which caused Beckett to make a noise that sounded akin to a growl.

'What do you mean?' Beckett asked, after a deep breath to calm herself.

'Well,' Lanie began, as she walked around the body, 'I have thoroughly checked him over for a needle mark and there is nothing, at all. So I thought it might have been ingested orally,' Castle sniggered at this, Beckett smacked him in the arm and he whined as he rubbed it, 'so,' Lanie continued, ignoring the couple, 'I checked his mouth and throat and there are no signs which is odd, then I checked his blood and nothing, there is no narcotic in his system.'

'So how did he die then?' Beckett asked, her frustration once more building, but now she also sounded intrigued.

'Well, from what I can tell, his heart just stopped beating,' Lanie said simply, causing Castle and Beckett to share one of those meaningful looks that meant 'WTF?'.

'You're telling me that he wasn't even murdered, he had a heart attack?' Beckett asked in disbelief.

'Not necessarily,' Lanie said in that cryptic way of hers, adding more mystery to this case, 'if he'd had a heart attack there is a high chance his skin would have a blue tinge. I'll know more after the autopsy, but I don't think this was a heart attack.'

'You're right Doctor,' a new voice said from behind them, no one had even heard the door opening, 'upon autopsy you would find that the heart is perfectly healthy with no signs of dead cells, therefore proving he did not die of a heart attack.'

The voice was British, and it made them all frown as they turned to look upon this newcomer. However when Castle met the man's eyes they both frowned at the immediate recognition.

'Potter!'

'Malfoy!'

'What?' Beckett and Lanie echoed.

'What are _you _doing here Potter!' The man, Malfoy apparently, asked, he was tall, very handsome, had white blond messy hair which was just below shoulder length and had piercing grey eyes. He looked around the same age as Castle.

'I live here, what are _you _doing here?'

'Live? Hah so this is where the famous boy hero ran off to! A morgue in New York!' The man, Malfoy, laughed loudly at this.

'Okay Castle what is going on?' Beckett asked, stepping forward and catching the man's eye, he whistled, 'this is your girlfriend Potter? Step up from the She-Weasel you tramped around with at school.'

'Malfoy,' Castle said, in that dangerous voice he rarely used around Beckett, 'why are you here?'

'Come on Potter I know you flunked at school but surely even you know this death is one of ours, I'm the liaison from the MoM,' Malfoy said, looking to Lanie, 'so pack up the body, I'm flying it back to Britain.'

'You can't do that! This is our case!' Beckett interjected, 'I can, and I will,' Malfoy said simply, 'does she know then?' he asked turning back to Castle.

'No,' Castle said, still in that menacing tone, 'she doesn't and she isn't finding out from you. Show me the papers.'

Malfoy didn't speak a word as he handed a sheet over to Castle which Beckett tried to grab, 'it's classified you stupid muggle,' Draco sneered.

'What did you call me?' Beckett asked fiercely, but Draco just sniggered as he leaned against the morgue wall.

'You? Really Malfoy? They hired you as head of the Department of Law Enforcement? An ex con and full time scumbag? Wow England has gone to the dogs since I left hasn't it?'

'Castle, you lived in England?' Beckett asked, still utterly confounded by what was happening, Castle seemed to have forgotten she was in the room.

'Aren't you listening woman? His name isn't Castle, it's Potter,' Draco sneered, as snarky and sharp as ever.

'I heard the rumours,' Malfoy said, jumping up onto one of the metal trolleys and getting comfortable, he was dressed in muggle clothing, a black fitting suit that looked like it had cost a fortune, with Malfoy it probably had, 'that the famous Potter had come out here and made a name for himself as a crime writer,' he snorted, 'Richard Edgar Castle,' he sniggered at this, '3 guesses how you came up with that name.'

'What's that supposed to mean? You don't know anything about me!' Castle said sharply.

'Really?' Malfoy challenged, 'Well Richard for your Grandfather on your Mother's side, and Edgar for your rich Gryffindor heir Grandfather,' he snorted, 'and Castle is obvious, for the castle you thought of as home in your lonely orphan days,' he laughed hard and Castle actually growled, 'Malfoy, take the damn body, go back to your England and your Ministry and never come back in my life again!' Castle said on a final note as he stormed out of the room.

Beckett rushed after her boyfriend and Malfoy took a sigh as he jumped down, he winked at a severely confused Lanie, 'so love, can I get that body now?'

* * *

Beckett caught up with Castle on the swings at the park across from the precinct, it was clear something was wrong and Beckett could tell it was big, especially with what had happened in the morgue.

'Castle who was that guy? And why did he say you aren't called Castle?'

'Because I'm not,' Castle said simply with a reserved sigh, 'I'm not Richard Castle, and Martha isn't my Mother…'

'And Alexis…'

'Oh, no!' Castle said shaking his head, 'she's my daughter, of course she is,' he spoke softly and a hint of a smile came over his face for the first time during the conversation both at the park and in the morgue.

'I need to tell you the whole story,' Castle admitted, 'but not here,' he added, 'back at the loft.'

Beckett nodded and got in the car with him which was parked across the road at the precinct, she drove and he looked out of the window and they didn't say a word until they were safely in the loft. Castle locked the door and made sure Martha and Alexis were out then he sat down at the table in the kitchen with Beckett and took a deep sigh.

'Kate, you have to promise me you won't call me insane, please hear me out,' Castle begged, he needed that promise before he began telling her that he wasn't the man she'd fallen in love with.

'I promise Castle,' Beckett said with a frown, 'I promise I'll believe you.'

Castle still wasn't sure she would, but it was something, and it meant he could begin, 'my real name is Harry James Potter, and the reason I changed it and why I'm here is because some bitch broke all of the rules and published my life story as a children's book.'

'Castle…' Beckett said slowly, 'are you saying…'

'I am saying the 'Harry Potter' series of books are real Beckett, they aren't fiction, they are my life,' Castle said, waiting for her to call a mental hospital or run away, but instead she gaped and said weakly, 'okay please explain.'

It was a better reaction than he'd initially imagined but he wasn't going to complain.

'Well…have you read the books?'

'Who hasn't?' Beckett said simply, causing Castle to roll his eyes and nod, 'a reporter called Rita Skeeter changed her name and wrote them, all about my life at Hogwarts and she has made millions from it, the scheming cow. She broke all of the rules of the statute of secrecy but by the time it was out it was too late and the ministry couldn't obliviate the whole bloody country.'

Beckett gaped at Castle as he jumped into an English accent, seemingly without knowing he'd done so. She wasn't sure if he was going insane or if she was, or if this was actually real but she'd agreed to hear him out so she would.

'Ginny and I couldn't handle it, wherever we went in the UK, we just couldn't hide from it,' Castle sighed, closing his eyes as he continued, 'so we moved over here but then of course it got big here too and we had to do all sorts to hide, change our names and even our appearances, then when Alexis was born something snapped. Ginny…she didn't want it anymore, so she left to go back to England, I think she's married now, but I don't know.

'So Meredith…'

'Is Ginny,' Castle confirmed, he didn't dare open his eyes to see the look on Beckett's face; she was probably looking at him like he was insane.

'Since Ginny left…I haven't talked to anyone from England, apart from Skeeter when I met her once at a book launch, and Malfoy today…that guy, it was 'Avada Kedavra' that killed him.'

'Wow, Castle…' Beckett trailed off and Castle opened his eyes to see her expression of shock, 'this is big, I mean wow.'

'You believe me?' Castle asked in surprise, Beckett raised her eyebrow at him, 'you gotta have more faith in me,' she said with a smile as she kissed him on the cheek, 'but we do need to talk about this.'

'I know,' Castle said, nodding vigorously, 'and I fully intend to have that conversation and not run away from it, scouts honour.'

'You were never in the scouts,' Beckett remarked, 'So?' Castle said in that playful way that made Beckett smile no matter how she was feeling.

'You need to go talk to him, before he leaves,' Beckett said after a moment of silence, 'you need to know how everything is, back…home.'

'It isn't home Kate,' Castle said with a light kiss to her lips, 'New York is, and it has been for a good while.'

Beckett smiled as she kissed him back, Castle withdrew from the kiss and sighed as he grabbed his jacket, 'but you are right, I'll see you tonight,' he kissed her on the cheek, whispered, 'I don't deserve you,' and left the loft to hunt down Draco Malfoy.

It didn't take long considering the Slytherin was waiting outside of his apartment block.

'Draco,' Castle said politely as they walked together in the direction of the park around the corner.

'Harry,' Draco returned, stiff like he wasn't used to the word which made Castle smile a little.

'I didn't choose to run away, I was forced too,' Castle said simply as they reached the green area and walked side by side, both with their hands in their pockets.

'Oh I know, the papers have mostly forgotten about you, occasionally there's a false sighting and your name always comes up on the anniversary of the final battle, and Halloween, of course,' Draco said matter of factly.

'Hm, and my friends?' Castle asked.

'Typical. Weasel vows he'll never take you back for what you did to his sister,' Draco said, causing Castle to snort, 'what I did? She's the one who ran off and married some millionaire and only visits her daughter once every 3 years.'

'That millionaire is Longbottom, they have a baby now,' Draco informed him, Castle snorted again, 'I'm perfectly happy with Alexis and Kate, good luck to her. How is Neville a millionaire by the way?'

Draco rolled his eyes, 'he own St. Mungo's,' he admitted reluctantly.

Castle laughed, 'I thought you'd have gotten that one?'

'Sadly can't be head of Magical Law Enforcement and St. Mungo's,' Draco said, making Harry chuckle.

'Your appearance is different,' Draco commented on, making Harry raise an eyebrow, 'I'm older, my hair is falling out, what do you expect? Although you look exactly the same, spitting image of your dear Daddy.'

Draco gave a bitter laugh, 'you changed your eye colour, and your hair colour.'

Castle shrugged, 'people see jet black hair and green eyes and who do they think of?'

'Guess you have Skeeter to thank for that, bet you want to kill her' Draco remarked.

'Wish I could,' Castle muttered, 'snapped my wand in half when I left England.'

'That was stupid,' Draco commented, 'if any ex Death Eaters come looking for you then you are unable to defend yourself.'

'They won't find me,' Castle said simply, 'unless that is, you tell them.'

'Me?' Draco asked sarcastically, 'you'd think I had a history as a scumbag, as you so eloquently put it earlier, America is rubbing off on you, although your English accent is flawless.'

'It's a skill,' Castle said with a small smile, 'Do you know how Hermione is?'

Draco smirked, 'Ah, as a matter of fact yes, she's fine. Married now with 2 children.'

'Really?' Castle asked with a smile, 'what are they called?'

'Scorpius and Cassiopeia,' Draco said, concealing his smirk as Castle frowned, 'What? Who would call their kids such stupid names?'

Castles eyes widened as they reached the most remote part of the park, 'Malfoy you wouldn't…you didn't…'

'Didn't what?' Malfoy asked innocently.

'You did, you wanker!'

'Ah those are the English insults I miss so much,' Draco said with a false air of sentimentality.

Castle was glaring at him now as he got ready to apparate, 'I'll give my love to Hermione for you,' Draco said with a smile.

The last thing he heard as he whooshed back to England was…

'You married my best friend you prick!'

_**The End!**_

_**A/N: this is oneshot, there won't be any more to it, I'm definitely not gonna continue it, sorry! But hope you enjoyed it and it isn't too OOC, It's hard to keep it in when you're doing as crazy a crossover as this one!**_

_**Peace out!**_


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